Assisting in vitro fertilization by manipulating cumulus-oocyte-complexes either mechanically or enzymatically does not prevent IVF failure [Kümülus-oosit-komplekslerinin mekanik veya enzimatik olarak manipulasyonuyla invitro fertilizasyona yardi{dotless}mci{dotless} olmak IVF başari{dotless}si{dotless}zli{dotless}ǧi{dotless}ni{dotless} önlemez]

Objective: this prospective study was set up in order to analyze whether additional treatment (cutting off supernumerous cumulus cells; adding hyaluronidase) of the cumulus-oocyte-complex (coc) would help to improve treatment outcome. material and methods: cocs from 50 patients were prospectively subdivided into a control group a (no manipulation of coc) and two study groups. in group b,surplus cumulus cells were cut off using syringes,and in the second study group cocs were incubated with a 1:11 dilution of hyaluronidase (final concentration 7 iu/l). main outcome measures were fertilization rate,embryo development,as well as rates of implantation,pregnancy,and live birth. results: fertilization was higher in group c as compared to the untreated control group a (p<0.05). however,complete fertilization failure could not be avoided by any of the modified ivf approaches. compaction on day 4 and blastocyst quality on day 5 were significantly improved in group c as compared to group b (but not to group a). rates of implantation,pregnancy,and live birth were not affected by any of the methods. conclusion: icsi seems to be the only choice for avoiding the vast majority of fertilization failures after ivf. © 2011 by the turkish-german gynecological education and research foundation.